The present invention relates to a fluid management and component detection system used during a surgical procedure. The present invention particularly relates to injector systems and devices used to detect and monitor injector components and fluids, such as contrast media, during an injection procedure.
Angiography is a procedure used to specifically image, diagnose and treat abnormalities in the heart or vascular structures. In recent decades, radiologists, cardiologists and vascular surgeons have also used angiography procedures to guide minimally invasive surgery of the blood vessels and arteries of the heart. During angiography, a physician inserts a catheter and injects a contrast material into a vein or artery of a patient. The vascular structures fluidly connected with the vein or artery in which the injection occurred are subsequently filled with the contrast material. Next, the area of the patient""s body injected with the contrast material is imaged using x-ray energy, whereby the radiation beam passes through the tissue of the patient and is absorbed by the contrast material. The resulting image or radiographic outline of the blood vessel is recorded onto film or videotape and/or displayed on a fluoroscope monitor. The images can be used for many purposes, as for example diagnostics and interventional procedures such as angioplasty, wherein a balloon is inserted into a vascular system and inflated to open a stenosis.
Various manual and automated injection systems used for performing angiography procedures are known in the art. Most current systems include a syringe and other disposable components (such as manifold tubing, spikes, etc.) operatively connected to a catheter. The syringe is filled by creating a vacuum which causes the contrast media to be suctioned into the chamber of the syringe. Any residual air is ejected from the chamber before connecting the syringe to the patient catheter. Once the system is completely set-up and primed, the syringe is connected to the patient catheter and the contrast media is injected into the target area.
The volume and flow rates of contrast media injections vary depending on patient parameters (such as heart/chamber/vasculature size, patient weight and physical condition) and type of treatment or diagnosis performed. Due to the variability of these parameters, it is often difficult to calculate the precise amount of contrast media needed for a particular patient and procedure. As a result, there exists the potential that the syringe chamber will be either under-filled or over-filled for a particular patient and/or procedure.
If the chamber is under-filled, an insufficient volume of contrast media will be injected into the patient, resulting in a less than optimal image and requiring that the procedure be repeated. This is not only expensive due to the high cost of contrast media, but is also potentially harmful to the patient in view of the additional radiation exposure and contrast dose injected into the patient. Conversely, if the syringe is over-filled, there will be an excess volume of contrast media remaining in the syringe after completion of the imaging procedure. To avoid patient contamination and product adulteration, the remaining volume of contrast media is simply discarded. Although over-filling the syringe avoids the problem of having to repeat the imaging procedure, over-filling wastes contrast media which is costly to hospitals and health care facilities.
Typically, contrast media is supplied in fluid volume containers having a 50 ml, 100 ml, 250 ml or 500 ml capacity. In contrast, patient procedures characteristically require as little as tens of milliliters to as much as hundreds of milliliters of fluid per procedure. The limited container volumes in conjunction with the variability associated with patient procedures often result in wasted fluid. For example, if a procedure requires 150 ml of fluid and a 250 ml container is used, the amount of fluid remaining in the container at the end of the procedure is discarded due to possible cross-contamination and fluid-crystallization issues. The discarded, unused portion not only wastes fluid, but also significantly contributes to increased hospital costs.
In addition to cost issues, the medical community is also faced with contamination problems associated with imaging procedures and, more particularly, the injector systems used to dispense the fluids. For example, the syringe, tubing and ancillary injector components used during imaging procedures are in fluid-communication with the patient. As a result, these items must be discarded after each case in order to avoid patient and/or product contamination, a potential risk confronting all products used during invasive procedures. Another reason for disposing of these items after a single use is that the majority of the imaging components are made of materials that are incompatible with state-of-the-art cleaning and resterilization procedures and, therefore, cannot be reused.
Although presently available injector systems are well accepted by the medical profession and function as required, it is desirable to have a more cost-effective injector system that is also safe and efficacious to use. In particular, it is desirable to have an injector system with a reservoir of contrast media that allows more than one patient to be injected using the same reservoir supply. It is also preferred that the system accommodate a variety of reservoir/container designs and fluids having various volumes, concentrations, viscosities, etc. It is also essential that the contrast media/fluid supply remain contamination-free during each use. In addition, it is desirable to have an injection system with a variety of accessory components that are single use, multiple use and resterilizable. Further, it is preferred that the system perform both diagnostic and non-diagnostic procedures, such as x-ray procedures. CT scanning, magnetic resonance imaging, ultrasonic imaging, angioplasty, saline ablation, etc., and is capable of using a variety of fluids, such as contrast media, saline, flushing fluids, etc.
In view of the foregoing, it is an object of the present invention to provide an injector subassembly that addresses the obstacles and disadvantages associated with current fluid injection practices.
A further object of the present invention is to provide an injector subassembly that is cost-effective, safe and efficacious to use.
A further object of the present invention is to provide an injector system with a reservoir of contrast media that allows more than one patient to be injected using the same reservoir supply.
A further object of the present invention is to provide a system that can accommodate a variety of reservoir/container designs and fluids having various volumes, concentrations, viscosities, etc.
A further object of the present invention is to provide a system wherein the contrast media/fluid supply remain contamination free during each use.
The present invention attempts to address these objects and other objects not specifically enumerated herein through the use of an injector subassembly used with an injector system, wherein the injector subassembly comprises a single use portion and a multiple use portion. In particular, the single use portion is fluidly connected to the multiple use portion, and the single use portion includes a high pressure tube connected to a catheter connection and the multiple use portion includes a syringe connected to a fluid supply reservoir. Further, the syringe and high pressure tube of the system are configured to be in fluid communication at a predetermined period of operation.
Another embodiment of the present invention contemplates an injector subassembly wherein a length of the high pressure tube is related to a pressure drop along the length of the tube.
Another embodiment of the present invention contemplates a multiple use portion that can be reused up to approximately five times.
Another embodiment of the present invention contemplates a multiple use portion that can be reused on one or more patients without cleaning or sterilizing the multiple use portion between each use.
Another embodiment of the present invention contemplates a single use portion that is supplied to a user of the subassembly as a kit.
Another embodiment of the present invention contemplates a multiple use portion that is supplied to a user of the subassembly as a kit.
The present invention also contemplates a syringe for use in an angiographic injector system, wherein the syringe comprises a syringe body having a distal end, a proximal end and a pumping chamber. In addition, a syringe plunger is located in the pumping chamber of the syringe and is movable along a path from the distal end to the proximal end of the syringe body. Further, the syringe plunger is connected to and controlled by a user-interface subassembly whereby the syringe plunger automatically disconnects from the syringe body when the syringe body has been used for a maximum number of uses.
The present invention also contemplates an angiographic injector system that tracks the volume of fluid injected into a patient or dispensed by the system, wherein the injector system comprises a user-interface subassembly and a reservoir containing fluid used during an injection procedure. In addition, the system includes a syringe fluidly connected to the reservoir and a patient, wherein the syringe includes a syringe plunger movable within the syringe. Further, the system also includes a syringe holder that holds the syringe in place on the injector system, whereby the syringe holder includes at least one electrical device that tracks the volume of fluid dispensed by the syringe via movement of the syringe plunger.
The present invention also contemplate an angiographic injector system comprising an injector subassembly and a user-interface subassembly wherein the user-interface subassembly includes a resume feature that allows for the recovery of the system from an error condition or power down.